DS0

from The Free On-line Dictionary of Computing (8 July 2008)
DS0

   <communications> The zeroth {DS level}, having a transmission
   rate of 64,000 bits per second (64 kb/s), intended to carry
   one {voice channel} (a phone call).

   (2001-03-18)
    
from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)
DS0
       Digital Signal level 0 (ISDN, T1), "DS-0"
       
    

[email protected]